The Western Electric Health Study began as a prospective epidemiologic investigation of coronary heart disease in 1958 with examination of 2,107 male employees aged 40-55 years. The Minnesota Multiphasic Personality Inventory (MMPI) was included in the 1958 examination, the Cattell 16 Personality Factor Questionnaire in the 1959 examination, a social factors questionnaire in 1960, and the MMPI again in 1962. Questionnaires from participants of next-of-kin and death certificates will be used in 1978-79 to identify possible incident cases of cancer; medical and hospital and records will be reviewed for information about diagnosis, treatment, and course of the disease. A total of 246 incident cases are expected. Two separate hypotheses will be investigated: (1) that psycholgical depression, as measured by the D scale in the 1958 MMPI, is associated with increased 20-year risk of cancer, and (2) that characteristic use of denial and repression, as assessed by Welsh's Factor R in the 1958 MMPI, is similarly related to increased risk of cancer. In addition, item analysis and discriminant analysis will be used to search for other aspects of personality that may be related to cancer incidence. Factors such as age, smoking habits, consumption of alcohol, and educational attainment will be taken into account. Analyses will be conducted for all cases of cancer together and, where numbers are adequate, for site-secific categories. The results of this study will help to establish whether previous findings concerning the association of psychologicl factors cancer were artifacts of the retrospective method or whether these previous findings, in fact, represent premorbid psychological characteristics of persons who develop cancer.